AC not working as cool as it should and can see sloshing in the sight glass. 87 Pete 359. I hooked up hose but nothing happened. The compressor is not the round type, but the kind that looks like a little air comressor, maybe a York?? It has shut off valves in both inlet and outlet on the head. Do you have to screw in the valve to open up to let more refrigrant come in? At present it's in full open position. Thanks for any comment. LB